Production System

ABSTRACT

The production system of the present invention includes a single main conveying line ( 10 ) capable of defining a plurality of manual work areas (A) and capable of conveying workpieces (W), a shuttle ( 30 ) that holds a workpiece thereon and that reciprocates along the main conveying line, a shuttle conveying line ( 20 ) on which the shuttle is reciprocated over a predetermined distance, a plurality of automatic processing machines ( 40 ) that are disposed along the shuttle conveying line on the side opposite to the side on which the main conveying line is laid and that automatically apply a variety of process operations to the workpiece, and a plurality of display units ( 60 ) that are disposed adjacent to the manual work areas and that display information about process operations to be applied to the workpiece. According to this production system, a worker is prevented from performing an improper process operation, and the entire system process can be smoothly performed. Additionally, an increase or decrease in the number of pieces of equipment or the replacement of the equipment with another can be easily achieved in response to an increase or decrease in the amount of production or a change in the machine model.

TECHNICAL FIELD

The present invention relates to an article production system in whichautomated process operations performed by a plurality of automaticprocessing machines and manual process operations performed by aplurality of workers are mixed together, and, more particularly, to aproduction system including shuttles that convey workpieces whilereciprocating at high speed.

BACKGROUND ART

A production system is known as a conventional production system thatmanufactures vehicle engines or the like. In this production system, asshown in FIG. 1, a plurality of automatic processing machines 2 thatapply various process steps, such as machining, attachment of parts,screw loosening, and screw tightening, onto workpieces W, such as enginecylinder blocks or engine cylinder heads, are arranged along a conveyingline 1 that conveys workpieces W. A manual work area 3 in which workersM can perform various process operations by manual work is locatedbetween the automatic processing machines 2.

In this production system, since the automated process steps and themanual process steps are connected in series with each other, theabsence of any one of these process steps causes a stoppage in the flowof the whole of the system, and, since the system has an arrangementstructure in which the manual work area 3 (i.e., the manual processstep) is located between the automatic processing machines 2, one workerM has difficulty in performing a plurality of manual process operationsacross the automatic processing machine 2. Therefore, a conventionalproblem resides in the fact that it is difficult to efficiently stationthe workers M, for example, when a production adjustment is required tobe carried out in response to a demand drop in the market.

Additionally, in one conveying line, workpieces W being conveyed on theupstream side in the line flow must be awaited until all processoperations to be performed by the automatic processing machine 2 arecompleted if the automatic processing machine 2 that has a plurality ofprocessing functions is disposed. Additionally, when the automaticprocessing machine 2 is replaced by another in accordance with a changein specifications of the workpiece W or a change in the machine model,all conveying lines must be stopped. Therefore, another conventionalproblem resides in the fact that it is not easy to increase the amountof production in response to a demand rise in the market and that it isnot easy to change the automatic processing machine 2 or add a newmachine so as to be suited to workpieces W.

On the other hand, a production system is known as a production systemcapable of increasing and decreasing the number of pieces of equipmentin accordance with an increase and decrease in the amount of production.This production system includes one conveying line having shuttles thatconvey workpieces, an automatic processing machine that is disposed onone side of the conveying line and that automatically performs aplurality of process operations, and a plurality of manual work standsthat are disposed on the opposite side of the conveying line and inwhich workers perform various process operations by their hands (seeJapanese Unexamined Patent Publication No. 2001-18869, for example).

However, in this production system, the manual work stands are disposedto be adjacent to each other on the same side. Therefore, there is afear that a worker will apply faulty handling to a workpiece conveyed toa manual work stand by a shuttle without following a correct procedure(for example, a process step to be performed in a subsequent manual workarea will be performed prior to a proper process step, or a worker incharge of a manual work area will perform a series of process operationsin improper order). Additionally, workpieces are all transferred byshuttles between the automatic processing machine and the manual workstand and between the two manual work stands. Therefore, it is difficultto, for example, smoothly convey a workpiece, which has undergone faultyprocessing, to a manual work stand located on the upstream side in orderto apply an alteration to this workpiece, and hence it is impossible tosmoothly apply the entire process steps to the workpiece.

DISCLOSURE OF INVENTION

The present invention has been made in consideration of thecircumstances of the conventional system. It is therefore an object ofthe present invention to provide a production system for producing motorvehicles, electric equipment, or their components in a state of mixingautomated process steps and manual process steps together. In thisproduction system, a worker can be prevented from performing an improperoperation, and the process steps of the whole of the system can besmoothly performed. Additionally, in this production system, the numberof pieces of equipment can be easily increased and decreased inaccordance with an increase and decrease in the amount of production, orthe equipment can be easily replaced with another in accordance with achange in machine model.

A production system of the present invention that achieves theabove-mentioned object includes a main conveying line capable ofdefining a plurality of manual work areas and capable of conveyingworkpieces, a shuttle conveying line laid over a predetermined distancealong the main conveying line, a shuttle that holds a workpiece thereonand that reciprocates on the shuttle conveying line, a plurality ofautomatic processing machines that are disposed along the shuttleconveying line and that automatically apply a variety of processoperations to the workpiece, and a display unit that is disposedadjacent to the manual work area and that displays information about aprocess operation to be applied to the workpiece.

According to this structure, a workpiece conveyed from the upstream sideof the main conveying line is automatically or manually transferred to ashuttle, and is conveyed to a predetermined automatic processing machineby allowing the shuttle to move on the shuttle conveying line. When theautomatic processing machine completes an automated process operation,the workpiece is again placed on the shuttle, and is transferred to amanual work area on the main conveying line. In this manual work area, aworker applies a predetermined manual process operation to the workpiecewhile confirming process information displayed by the display unit.Thereafter, the workpiece is again placed on the shuttle, and isconveyed by the shuttle to the same or another automatic processingmachine. The automatic processing machine performs and completes anotherautomated process operation. The workpiece is again placed on theshuttle, and is transferred to another manual work area on the mainconveying line. Thus, a series of manual process operations andautomated process operations can be performed correlatively andsmoothly, and productivity can be raised. Especially, the display unitenables the worker to obtain process information. Therefore, the processoperations can be monitored so that the entire system process can beperformed reliably and smoothly, and, in addition, a process operationassigned to the worker can be performed while confirming the worksequence.

Additionally, since the shuttle and the shuttle conveying line aredisposed adjacent to the main conveying line by which a plurality ofmanual work areas can be defined, and since a plurality of automaticprocessing machines are disposed adjacent to the shuttle conveying linewhereby the shuttle conveying line is located between the automaticprocessing machines and the main conveying line, an increase or decreasein the number of workers and in the number of the automatic processingmachines or the replacement of the equipment with another can be easilyachieved in response to an increase or decrease in the amount ofproduction or a change in the machine model.

Preferably, in the structure mentioned above, the display unit may bedisposed with respect to each of the manual work areas.

According to this structure, since the display unit is provided for eachmanual work area, a worker in charge of each manual work area canascertain and obtain only process information concerning the manual workarea assigned to the worker (for example, the contents of the lastprocess operation performed by the automatic processing machine, thecontents of the last manual process operation, or the contents of amanual process operation to be performed in the manual work areaassigned to the worker). Therefore, the worker can confirm notinformation concerning the other manual work areas but only informationnecessary in the manual work area assigned to the worker, and hence canbe reliably prevented from applying a wrong process operation to aworkpiece, without being deluded by information not directly linkedthereto.

Preferably, in the structure mentioned above, the display unit maydisplay information about a manual process operation that is applied toa workpiece.

According to this structure, a worker in charge of each manual work areacan confirm the contents of a manual process operation in the manualwork area assigned to the worker, and hence can correctly perform thepredetermined manual process operation. Therefore, even when a manualwork area is assigned to a worker inexperienced in this manual workarea, the worker can perform a process operation while confirming thecontents of this process operation shown by the display unit.

Preferably, in the structure mentioned above, when a faulty manualprocess operation is applied to a workpiece, the display unit maydisplay information showing this faulty manual process operation.

According to this structure, when a faulty manual process operation isapplied to a workpiece, the display unit informs the worker of this, andhence the worker can immediately take the suitable countermeasures.

Preferably, in the structure mentioned above, a connection conveyingline that is a connection formed between the main conveying line and theshuttle conveying line and that conveys a workpiece may be provided inan area corresponding to each of the automatic processing machines.

According to this structure, since the connection conveying linetransfers a workpiece between the main conveying line and the shuttle,the workpiece can be conveyed more smoothly between the manual work areaand the automatic processing machine.

Preferably, in the structure mentioned above, the connection conveyingline may include a connection carry-out line extending from the mainconveying line toward the shuttle conveying line and a connectioncarry-in line extending from the shuttle conveying line toward the mainconveying line.

According to this structure, the connection carry-out line performs acarry-out operation of a workpiece when this workpiece is carried outfrom the manual work area toward the shuttle (or toward the automaticprocessing machine). On the other hand, the connection carry-in lineperforms a carry-in operation of a workpiece when this workpiece iscarried in from the shuttle (or from the automatic processing machine)toward the manual work area. Therefore, the pre-provision of a pluralityof shuttles makes it possible to simultaneously perform a carry-outoperation and a carry-in operation of a workpiece between the manualwork area and the shuttle (or the automatic processing machine), thusmaking it possible to smooth the flow of workpieces.

Preferably, in the structure mentioned above, the production system mayfurther include a control means for performing the whole control overworkpiece processing, and, when a faulty manual process operation isapplied to a workpiece, the control means drive-controls the connectionconveying line and the shuttle so as to again return the workpiece to acorresponding manual work area.

According to this structure, for example, a workpiece that has undergonea faulty process operation at the preceding step is again returned to acorresponding manual work area located on the upstream side via theconnection conveying line and the shuttle. Therefore, an alteringoperation can be smoothly performed in the series of flow process steps.

Preferably, in the structure mentioned above, the automatic processingmachines and the shuttle conveying line may form a related automaticprocessing station, whereas the manual work areas and the display unitmay form a related manual workstation, and the automatic processingstation and the manual work station may be disposed at a plurality ofplaces along the main conveying line.

According to this structure, since the automatic processing stations andthe manual work stations are arranged along the single main conveyingline, workpieces can be conveyed on the main conveying line, andmutually-related process operations can be performed in each of theautomatic processing stations and the manual work stations, thus makingit possible to smoothly perform the series of process steps and to raiseproductivity.

Preferably, in the structure mentioned above, the shuttle conveyinglines included in the automatic processing stations disposed at theplurality of places may be connected to each other.

According to this structure, when a workpiece is transferred between theautomatic processing station located on the upstream side and theautomatic processing station located on the downstream side, theworkpiece can be transferred not only by using the main conveying linebut also by using the shuttle conveying line (i.e., shuttle). Therefore,the workpiece can be more smoothly conveyed.

Preferably, in the structure mentioned above, the display unit may behung from a guide member provided along and above the main conveyingline so that the display unit is hung so as to be freely moved and fixedwith respect to the guide member.

According to this structure, since the display unit is hung above themain conveying line, i.e., above the manual work area without beingplaced on, for example, the ground surface, a worker can freely move soas to raise working efficiency without being subjected to restrictionson mobility that are caused by the display unit.

Preferably, in the structure mentioned above, the automatic processingmachine may include an assembling mechanism capable of automaticallyapplying at least one of assembly process operations selected from apart attaching operation, a part detaching operation, a screw tighteningoperation, and a screw loosening operation onto an engine cylinder blockor an engine cylinder head.

According to this structure, in the production system that automaticallyperforms an engine assembly operation, productivity can be raised, andan increase or decrease in the number of pieces of equipment or thereplacement of the equipment with another can be easily achieved inresponse to an increase or decrease in the amount of production ofengines or a change in the machine model.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view showing a conventional production system.

FIG. 2 is a perspective view showing an embodiment of a productionsystem according to the present invention.

FIG. 3 is a cross-sectional view showing a part of the production systemshown in FIG. 2.

FIG. 4 is a block diagram of a control system of the production systemshown in FIG. 2.

FIG. 5 is a plan view showing the flow of workpieces in the productionsystem of FIG. 2.

FIG. 6 is a perspective view showing another embodiment of theproduction system according to the present invention.

FIG. 7 is a perspective view showing still another embodiment of theproduction system according to the present invention.

FIG. 8 is a perspective view showing still another embodiment of theproduction system according to the present invention.

FIG. 9 is a perspective view showing still another embodiment of theproduction system according to the present invention.

FIG. 10 is a perspective view showing still another embodiment of theproduction system according to the present invention.

FIG. 11 is a perspective view showing still another embodiment of theproduction system according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be hereinafterdescribed with reference to the accompanying drawings.

As shown in FIG. 2 to FIG. 4, this production system includes a mainconveying line 10 that can define a plurality of manual work areas A andthat can convey workpieces W, a shuttle conveying line 20 laid over apredetermined distance along the main conveying line 10, a shuttle 30that carries a workpiece W thereon and that reciprocates on the shuttleconveying line 20, a plurality of automatic processing machines 40 thatare disposed along the shuttle conveying line 20 and that automaticallyapply various process operations to workpieces W, a connection conveyingline 50 that conveys workpieces W while serving as a connection betweenthe main conveying line 10 and the shuttle conveying line 20, a displayunit 60 that is disposed adjacent to the manual work area A and thatdisplays information concerning the processing of workpieces W, and ahost computer 100 serving as a control means for controlling the entiresystem.

In this embodiment, an engine cylinder block, an engine cylinder head,or its related component, which is mounted on, for example, a vehicle,is used as a workpiece W to be processed.

As shown in FIG. 2 to FIG. 4, the main conveying line 10 can conveyworkpieces W received automatically by use of transfer equipment ormanually from the upstream side in the system flow toward the downstreamside, and defines a plurality of manual work areas A in each of which aworker M performs manual process operations assigned to the worker M.Accordingly, the worker M can stand adjacent to the main conveying line10 on one side of the main conveying line 10. Each of the manual workareas A is located to correspond to each of the automatic processingmachines 40 described later (i.e., is located to face each of them).

The main conveying line 10 is a roller type conveyer, and is providedwith a stop mechanism that stops a workpiece W in a manual work area A.The main conveying line 10 is additionally provided with a drivingmechanism 11 that automatically conveys a workpiece W between the manualwork areas A. The driving mechanism 11 is connected to the host computer100, and is drive-controlled thereby.

The main conveying line 10 may have only a plurality of rollers, and aworker M may push a workpiece W on the rollers to convey this.

As shown in FIG. 2 to FIG. 4, the shuttle conveying line 20 is laid overa predetermined distance along the main conveying line 10 on the sideopposite to the side on which a worker M stands. The shuttle conveyingline 20 has a driving mechanism 21 that reciprocatively guides a shuttle30 capable of holding a workpiece W thereon at high speed. The drivingmechanism 21 is connected to the host computer 100, and isdrive-controlled thereby.

A driving mechanism by linear motors, a driving mechanism by superhigh-speed ball screws, a driving mechanism by belts, a drivingmechanism by gears, or other types of driving mechanisms can be employedas the driving mechanism 21 that reciprocates a shuttle 30 at highspeed.

The shuttle 30 may have a mechanism that assists the carry-in operationof a workpiece W when the workpiece W is held and a mechanism thatassists the carry-out operation of a workpiece W when the workpiece W istransferred. A plurality of shuttles 30 may be provided on the singleshuttle conveying line 20 so that each of the shuttles 30 isdrive-controlled to be freely reciprocated.

As shown in FIG. 2 to FIG. 4, in order to transfer a workpiece W betweenthe manual work area A and the shuttle 30, the connection conveying line50 is located between the main conveying line 10 and the shuttleconveying line 20 at a place corresponding to each of the automaticprocessing machines 40.

The connection conveying line 50 is made up of a connection carry-outline 51 that carries a workpiece W out from the main conveying line 10toward the shuttle conveying line 20 and a connection carry-in line 52that carries a workpiece W in from the shuttle conveying line 20 towardthe main conveying line 10.

In detail, the connection carry-out line 51 performs a carry-outoperation of a workpiece W when this workpiece W is carried out from themanual work area A toward the shuttle 30 (or toward the automaticprocessing machine 40). On the other hand, the connection carry-in line52 performs a carry-in operation of a workpiece W when this workpiece Wis carried in from the shuttle 30 (or from the automatic processingmachine 40) toward the manual work area A. Therefore, the pre-provisionof a plurality of shuttles 30 makes it possible to simultaneouslyperform a carry-out operation and a carry-in operation of a workpiece Wbetween the manual work area A and the shuttle 30 (or the automaticprocessing machine 40), thus smoothing the flow of workpieces W.

As shown in FIG. 2 to FIG. 4, a plurality of automatic processingmachines 40 are disposed along the shuttle conveying line 20, and serveto automatically apply various process operations to workpieces Wtransferred from the shuttle 30. In this embodiment, the automaticprocessing machines 40 arranged adjacent to the shuttle conveying line20 that is used for each of the automatic processing machines 40 serveto apply a series of mutually-related process operations to workpiecesW.

As shown in FIG. 3, the automatic processing machine 40 includes amovable table 41 that moves a workpiece W transferred from the shuttle30 while holding the workpiece W thereon, an operation unit 42 thatapplies a variety of automated process operations to workpieces W, acomponent storage container 43 that stores components when necessary,and an articulated robot (not shown) that transports components from thecomponent storage container 43 to a workpiece W. As shown in FIG. 4, theautomatic processing machine 40 is connected to a sub-computer 44 thatcontrols the driving of the movable table 41 and each process operation.The sub-computer 44 is connected to the host computer 100 so that thewhole of the sequences can be controlled.

The movable table 41 receives a workpiece W from the shuttle 30, thenbrings in the workpiece W so as to occupy a predetermined processingposition, and positions the workpiece W. After completing apredetermined process operation, the movable table 41 again transfersthe workpiece W toward the shuttle 30.

The operation unit 42 applies a predetermined automated processoperation to a workpiece W, depending on this workpiece W. If thisworkpiece W is an engine cylinder block, the operation unit 42 mayinclude an assembling mechanism that performs at least one assemblingprocess operation, such as machining, the attachment and detachment ofcomponents, screw loosening, or screw tightening.

For example, to fit a crankshaft and a metal into the cylinder block,the automatic processing machines 40 can include an automatic processingmachine 40 that performs the screw loosening of a main cap which is anautomated process operation, an automatic processing machine 40 thatperforms the detachment of, for example, the main cap (i.e.,disengagement thereof from a fitted state) and the attachment of themain cap (i.e., fitting) which is an automated process operation, and anautomatic processing machine 40 that performs the screw tightening ofthe main cap which is an automated process operation.

In other words, a variety of mutually-related process operations (i.e.,automated process operations and manual process operations) can beperformed at high efficiency by the automatic processing machines 40arranged along the single shuttle conveying line 20, by the manual workareas A each of which is located in an area corresponding to each of theautomatic processing machines 40, and by the shuttle 30 that conveys aworkpiece W between the automatic processing machine 40 and the manualwork area A.

As shown in FIG. 2 to FIG. 4, the display unit 60 is disposed adjacentto the main conveying line 10 in each of the manual work areas A, and isconnected to the host computer 100. The display unit 60 is made up of amonitor, such as a liquid crystal monitor or a cathode-ray tube monitor,an operating button that can be operated by a worker M, etc.

For example, the switching of the operating button allows the displayunit 60 to visually display information about manual process operationsin a corresponding manual work area A (for example, a processingprocedure), information about manual process operations in a desiredmanual work area A, or information about automated process operations bythe automatic processing machine 40 in the form of letters or athree-dimensional animation.

Since the display unit 60 is provided in each of the manual work areasA, a worker M in charge of one of the manual work areas A can obtain,for example, the contents of the last process operation performed by theautomatic processing machine 40, the contents of the last manual processoperation in that manual work area A, or the contents of a manualprocess operation to be performed in the manual work area A assigned tothe worker M. Therefore, the worker M can obtain necessary informationin the manual work area A assigned to the worker M while confirming theprocess operations concerning the other manual work areas A, and hencefaulty process operations can be reliably prevented from beingperformed.

Since a worker M in charge of one of the manual work areas A can confirmthe contents of a manual process operation in that manual work area Aespecially by displaying information about the manual process operationto be applied to a workpiece W by use of the display unit 60, the workerM can correctly perform the predetermined manual process operation.Therefore, even when a manual work area A is assigned to a worker Minexperienced in this manual work area A, the worker M can perform aprocess operation while confirming the contents of this processoperation shown by the display unit 60.

If the display unit 60 is enabled to display the information that afaulty manual process operation has been applied to a workpiece W, aworker M can immediately take the most suitable countermeasures when theworker M is informed of the faulty manual process operation. Forexample, when a faulty process operation was performed in a manual workarea A antecedent to the manual work area A assigned to the worker M,the worker M in charge of the manual work area A subsequent thereto canissue an alteration command while manipulating the operating button ofthe display unit 60, and can issue a control command to return to themanual work area A where the workpiece W undergoes a necessaryalteration. Therefore, in the manual work area A where the workpiece Wis required to undergo a necessary alteration, the information of“Alteration Required” is displayed by the display unit 60, thus makingit possible to apply a necessary alteration to the workpiece W returnedthereto.

FIG. 5 shows a system flow followed when manual process operations,automated process operations, and alteration process operations areapplied to workpieces W in the production system formed as mentionedabove.

In detail, when a workpiece W conveyed from the upstream side of themain conveying line 10 reaches a first manual work area A, a worker Mperforms a predetermined manual process operation while confirming thecontents of the process operation, a work sequence, etc., that are shownby the display unit 60.

Thereafter, the workpiece W that has undergone the manual processoperation is transferred to a shuttle 30 via a first connectioncarry-out line 51. The shuttle 30 then conveys the workpiece W to afirst automatic processing machine 40.

When a variety of automated process operations are completed by thisautomatic processing machine 40, the shuttle 30 receives and transfersthe workpiece W to the main conveying line 10 via a first connectioncarry-in line 52. The workpiece W is then conveyed to a second manualwork area A.

Thereafter, a worker M in charge of the second manual work area Aperforms a predetermined manual process operation while confirming thecontents of the process operation, a work sequence, etc., that are shownby the display unit 60. Herein, from the information shown by thedisplay unit 60, the worker M can also confirm whether the precedingmanual process operation has been correctly performed. If a faultyprocess operation has been applied to the workpiece W, an alterationcommand signal is input into the display unit 60, and allows the hostcomputer 100 to drive-control the connection carry-out line 51 and theshuttle 30 so as to again return the workpiece W to the previous manualwork area A. As a result, the workpiece W is again returned to theprevious manual work area A via the connection carry-out line 51 and theshuttle 30 as shown by the dotted line R of FIG. 5. The worker M maypass the workpiece W directly to the previous manual work area A via themain conveying line 10 as shown by the dotted line R′ of FIG. 5.

Since the display unit 60 is informed of the manual work area A in whicha faulty process operation has been performed, the worker M can apply anecessary alteration to the workpiece W returned thereto.

On the other hand, when the workpiece W that has undergone a properprocess operation reaches the second manual work area A, the worker Mapplies a predetermined manual process operation to the workpiece Wwhile confirming the contents of the process operation, a work sequence,etc., that are shown by the display unit 60.

Thereafter, the workpiece W that has undergone the manual processoperation is transferred to the shuttle 30 via a second connectioncarry-out line 51. The shuttle 30 then conveys the workpiece W toward asecond automatic processing machine 40 (or toward the first automaticprocessing machine 40 if an automated process operation is performed bythe first automatic processing machine 40).

After a variety of automated process operations are performed by thisautomatic processing machine 40, the shuttle 30 receives and transfersthe workpiece W to the main conveying line 10 via a second connectioncarry-in line 52. The workpiece W is then conveyed to a third manualwork area A.

In the third manual work area A, manual process operations are performedin the same way as above, and a series of mutually-related processoperations are completed.

When the series of process operations are completed, the workpiece W isconveyed on the main conveying line 10 toward its downstream side. Forexample, when another related process operation is applied to theworkpiece W, the workpiece W is conveyed to another manual work area Aand to another-automatic processing machine 40 that are located on thedownstream side of the main conveying line 10.

A series of manual process operations and automated process operationscan be performed correlatively and smoothly in this way, andproductivity can be raised. Especially, the display unit 60 enables theworker to obtain information concerning the process operations.Therefore, the process operations can be monitored so that the entireprocess can be performed reliably and smoothly, and, in addition, aprocess operation assigned to the worker can be performed whileconfirming the work sequence.

FIG. 6 shows another embodiment of the production system according tothe present invention. The same reference character is given to the samestructure as in the above embodiment, and a description of the same isomitted.

In detail, in this production system, a plurality of automaticprocessing stations S1, S2, and S3 and a plurality of manual workstations S1′, S2′, and S3′ are arranged along one main conveying line 10as shown in FIG. 6. A sub-station 110 used to perform an auxiliarymanual process operation is located on the side on which a worker M forthe main conveying line 10 is stationed.

The automatic processing stations S1, S2, and S3 are used to applydifferent automated process operations to workpieces W, and each stationhas a plurality of automatic processing machines 40, shuttles 30, and ashuttle conveying line 20.

The manual work stations S1′, S2′, and S3′ are used to apply manualprocess operations, which are correlated with the automatic processingstations S1, S2, and S3, respectively, to workpieces W. Each of themanual work stations has a plurality of manual work areas A and displayunits 60.

In this production system, a worker M is stationed to concurrently haveat least two manual work areas A. The reason is that the number ofworkers M is reduced, and workpieces W are conveyed in slow “takt time”when the amount of production is decreased.

Since the automatic processing stations S1, S2, and S3 and the manualwork stations S1′, S2′, and S3′ are arranged along the single mainconveying line 10 as described above, workpieces W can be conveyed onthe main conveying line 10, and a variety of mutually-related processoperations (i.e., automated process operations and manual processoperations) can be smoothly performed, thus making it possible toperform the series of process operations at high efficiency.

Additionally, since a worker M is stationed on one side of the singlemain conveying line 10, a plurality of manual work areas A can be easilyassigned to one worker M, and workers M can be efficiently stationed,thus making it possible to reduce production costs while suppressing arise in labor costs.

FIG. 7 shows an example taken when the amount of production is increasedin the production system of FIG. 6.

To increase the amount of production, workers M′ are additionallystationed in the manual work stations S1′, S2′, and S3′ and in thesub-station 110 in an appropriate manner, and workpieces W are conveyedin fast “takt time.”

Thus, workers M′ can be additionally stationed along the main conveyingline 10 with ease without changing the production system, and the amountof production can be increased in response to increasing demand.

FIG. 8 shows still another embodiment of the production system accordingto the present invention. To further increase the amount of production,automatic processing machines 40″, display units 60″, and sub-stations120 and 130 are added to the production systems shown in FIG. 6 and FIG.7. According to need, additional workers M″ are stationed.

As described above, the manual work stations S1′, S2′, S3′ (workers M,M′, and M″) are located on one side, whereas the automatic processingstations S1, S2, and S3 are located on the opposite side in the state inwhich the main conveying line 10 that can define a plurality of manualwork areas A is located between the manual work stations S1′, S2′, andS3′ and the automatic processing stations S1, S2, and S3. Therefore,additional workers M″ can be easily stationed, or automatic processingmachines 40″ can be easily added or changed when the amount ofproduction is increased or when the type of the automatic processingmachine 40 is changed.

FIG. 9 shows still another embodiment of the production system accordingto the present invention. In this embodiment, the shuttle conveying line20 in the production system of FIG. 8 is changed.

In detail, in this production system, a single shuttle conveying line20′″ is disposed for all of the automatic processing stations S1, S2,and S3 located at a plurality of places. The single shuttle conveyingline 20′″ can be formed by connecting the shuttle conveying lines 20mentioned in the above embodiment together.

According to this production system, when a workpiece W is transferredbetween the automatic processing station S1 (or S2) located on theupstream side and the automatic processing station S2 (or S3) located onthe downstream side, the workpiece W can be directly transferred byusing the shuttle conveying line 20′″, i.e., by using the shuttle 30without using the main conveying line 10. Therefore, the workpiece W canbe more smoothly conveyed.

FIG. 10 shows still another embodiment of the production systemaccording to the present invention. In this embodiment, a method ofarranging the display units is changed in comparison with the productionsystem of FIG. 2.

In detail, in the production system according to this embodiment, aguide rail 150 serving as a guide member extending in a substantiallyhorizontal direction is disposed along and above the main conveying line10 as shown in FIG. 10. A plurality of display units 160 are hung fromthe guide rail 150 so as to be movable on the guide rail 150, and arefixed in corresponding manual work areas A, respectively.

Since the display unit 160 is hung from the guide rail 150 above themain conveying line 10, i.e., above the manual work area A in this waywithout being placed on, for example, the ground surface, a worker M canfreely move so as to raise working efficiency without being subjected torestrictions on mobility that are caused by the display unit 160 actingalso as an obstacle.

FIG. 11 shows still another embodiment of the production systemaccording to the present invention. In this embodiment, the samereference character is given to the same structure as in the productionsystem of FIG. 2, and a description of the same is omitted. In detail,in the production system according to this embodiment, the shuttleconveying line 20 is disposed adjacent to the main conveying line 10 asshown in FIG. 11, and the connection conveying line 50 (the connectioncarry-out line 51 and the connection carry-in line 52) shown in FIG. 2is removed.

According to this production system, a workpiece W conveyed from theupstream side of the main conveying line 10 to the manual work area A issubjected to a predetermined manual process operation, and istransferred to the shuttle 30 by the manual work of a worker M. Theshuttle 30 is then moved on the shuttle conveying line 20, so that theworkpiece W is conveyed to a predetermined automatic processing machine40.

When this automatic processing machine 40 completes an automated processoperation, the workpiece W is again placed on the shuttle 30, and istransferred to the second manual work area A on the main conveying line10. In the second manual work area A, a worker M performs apredetermined manual process operation while confirming processinformation displayed by the display unit 60, and hands over theworkpiece to the shuttle 30 again.

Thereafter, the shuttle 30 conveys the workpiece W to the same oranother automatic processing machine 40. When the automatic processingmachine 40 performs and completes another automated process operation,the workpiece W is again placed on the shuttle 30, and is transferred tothe third manual work area A on the main conveying line 10.

Accordingly, the system can be simplified by removing the connectionconveying line 50 mentioned above, and a series of manual processoperations and automated process operations can be correlativelyperformed, thus achieving a rise in productivity. Although a burdenimposed on the worker M is increased in accordance with the removal ofthe connection conveying line 5 b, this system is suitable especiallyfor a case in which a relatively lightweight workpiece W is subjected toa series of process steps.

In the embodiments mentioned above, a description has been given of theproduction system in which an engine cylinder block or an enginecylinder head is used as a workpiece W. However, without being limitedto this, the present invention can be applied to a production system inwhich other engine parts, pieces of electric equipment, etc., are usedas workpieces W.

In the above embodiments, the figures show an example in which three orfour automatic processing machines 40 and 40″ are included in theautomatic processing stations S1, S2, and S3. However, without beinglimited to this, five or more automatic processing machines 40 may beincluded therein in accordance with the contents of process operations.

In the above embodiments, an example is shown in which the threeautomatic processing stations S1, S2, and S3 are disposed for the singlemain conveying line 10. However, without being limited to this, four ormore automatic processing stations and a plurality of correspondingmanual work stations may be provided in accordance with a workpiece W tobe subjected to process operations so that a series of automated processoperations and manual process operations can be smoothly performed.

INDUSTRIAL APPLICABILITY

As described above, the production system of the present invention hasmanual process operations and automated process operations mixedtogether. According to this production system, the entire process can besmoothly performed, and an increase or decrease in the number of piecesof equipment or the replacement of the equipment with another can beeasily achieved in response to an increase or decrease in the amount ofproduction or a change in the machine model. Therefore, the presentinvention is, of course, applicable to a production system for use inthe industrial fields of motor vehicles, electric equipment, etc., andis useful as a production system for use in other fields having a needto perform process operations while conveying workpieces.

1. A production system comprising: a single main conveying line capableof defining a plurality of manual work areas and capable of conveyingworkpieces; a shuttle conveying line laid over a predetermined distancealong the main conveying line; a shuttle that holds a workpiece thereonand that reciprocates on the shuttle conveying line; a plurality ofautomatic processing machines that are disposed along the shuttleconveying line and that automatically apply a variety of processoperations to the workpiece; and a display unit that is disposedadjacent to the manual work area and that displays information about aprocess operation to be applied to the workpiece.
 2. The productionsystem according to claim 1, wherein the display unit is disposed withrespect to each of the manual work areas.
 3. The production systemaccording to claim 1, wherein the display unit displays informationabout a manual process operation that is applied to a workpiece.
 4. Theproduction system according to claim 1, wherein, when a faulty manualprocess operation is applied to a workpiece, the display unit displaysinformation showing the faulty manual process operation.
 5. Theproduction system according to claim 1, wherein a connection conveyingline that is a connection formed between the main conveying line and theshuttle conveying line and that conveys a workpiece is provided in anarea corresponding to each of the automatic processing machines.
 6. Theproduction system according to claim 5, wherein the connection conveyingline includes a connection carry-out line extending from the mainconveying line toward the shuttle conveying line and a connectioncarry-in line extending from the shuttle conveying line toward the mainconveying line.
 7. The production system according to claim 5, furthercomprising a control means for performing whole control over workpieceprocessing, wherein, when a faulty manual process operation is appliedto a workpiece, the control means drive-controls the connectionconveying line and the shuttle so as to again return the workpiece to amanual work area.
 8. The production system according to claim 1, whereinthe automatic processing machines and the shuttle conveying line form arelated automatic processing station, whereas the manual work areas andthe display unit form a related manual workstation, and the automaticprocessing station and the manual work station are disposed at aplurality of places along the main conveying line.
 9. The productionsystem according to claim 8, wherein the shuttle conveying linesrespectively included in the automatic processing stations disposed atthe plurality of places are connected to each other.
 10. The productionsystem according to claim 1, wherein the display unit is hung from aguide member provided along and above the main conveying line so thatthe display unit can be moved and fixed with respect to the guidemember.
 11. The production system according to claim 1, wherein theautomatic processing machine includes an assembling mechanism capable ofautomatically applying at least one of assembly process operationsselected from a part attaching operation, a part detaching operation, ascrew tightening operation, and a screw loosening operation onto anengine cylinder block or an engine cylinder head.